The challenge with high permittivity acceptors in organic solar cells: a case study with Y-series derivatives

Abstract

We synthesized high-permittivity Y-series acceptors and disclose that main reasons for the limited efficiency are others than altered bulk heterojunction morphologies.

A brominated M3 based non-fullerene acceptor: synthesis, material and photovoltaic properties

“…6. In the PM6:M3 as well as the PM6:C1 films, contributions of both neat materials are observed, which reveals that crystalline domains of the donor 57 and acceptor materials (see Fig. S1, ESI†) are present in the bulk heterojunction films.…”

A multifunctional thienothiophene member: 4-thieno[3,2-b]thiophen-3-ylbenzonitrile (4-CNPhTT)

“…A simple synthetic strategy developed by Öztürk’s group has shortened the cumbersome four-step synthetic method reported in the literature to two steps with high yields, which has particularly led to the introduction of various aryl and alkyl groups to the 3-position of thieno[3,2- b ]thiophene ( Scheme 1 ) [ 24 – 28 ]. This method has now been used by some groups and declared as a convenient method, with the synthesis being performed via alternative synthetic routes, simplifying the variation of the side chains of the outer thiophene site with a universal TT building block that can be produced with good yields from inexpensive starting materials [ 29 – 31 ]. Such substitutions caused remarkable changes in the electronic and optical properties of polymeric and small molecules constructed using TTs as building blocks [ 32 – 39 ].…”